Concentration of minerals



CLEMENT LIN'WOOD PERKINS, OF PITTSBURGH,

anrNr Price,

PENNSYLVANIA, ASSIGNOR T0 METALS RECOVERY COMPANY, OF NEW YORK, N. Y., ACORPORATION OF IBIIAINE.

CONCENTRATION OF MJIIERALS.

neeaeeo.

Specification of Letters Patent.

Patented Oct. 25, 11921.

No Drawing. Application filed December 3, 1918, Serial No. 265,165.Renewed March 12, 1921. Serial T 0 all whom it may concern:

Be it known that I, CLEMENT L. PERKINs, a citizen of the United States,residing at Pittsburgh, in the county of Allegheny, State ofPennsylvania, have invented certain new and useful Improvements inConcentration of Minerals; and I do hereby declare the following to be.a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

This invention relates to the concentration of minerals, such as sulfidores and the like, by flotation; and is based upon the discovery thatimproved results can be obtained by carrying out the flotation operationwith the addition to the ore or mineral pulp of a compound flotationagent made up of a mixture of two or more amino compounds, which agentis readily miscible with the water of the mineral pulp.

Certain flotation agents, for example, alphaand beta-naphthylamin,because of their solid character and their degree of insolubility,present certain difficulties in their uniform distribution throughoutthe ore pulp, although it is possible to effect such distribution and tocarry out the flotation operation with advantage by their use.

I have found that such solid amino compounds can be more readily, andwith advantage, distributed throughout the ore pulp by dissolving thesolid amino compound 1n a liquid amino compound which is readilymiscible with water; and the present invention, accordingly, provides amethod of facilitating the incorporation with the ore .pulp of, suchsolid amino compounds as flotation agents.

Among the liquid amino. compounds which may be referred to as solventsfor the solid amino compounds may be mentioned anilin, xylidin,toluidin, quinolin, pyridin, dimethylanilin, &c. The liquid aminocompounds may or may not in themselves be good flotation agents,although it will be evident that the process is one of added advantagewhere the liquid amino compound, as Well as the solid amino compound, isitself a good flotation agent.

The flotation agent which I consider most advantageous and asparticularly to be rec ommended in the process of the present inventionis a solution of alpha-naphthylamin in xylidin, and the invention willbe further described and illustrated in connection therewith. It is notnecessary that chemically pure alpha-naphthylamin be used, but thecommercial product may be used in its crude or unrefined state;similarly the xylidin can be used in its crude or unrefined state; butit will be evident that the compound flotation agent should be free fromimpurities prejudicial to the flotation operation.

The proportions of alpha-naphthylamin and xylidin can be varied, forexample, between 70 parts of al ha-naphthylamin dis solved in 30 parts 0xylidln, and 30 parts of alpha-naphthylamin dissolved in 70 parts ofxylidin. The proportions which I have found of particular value'areabout 60 parts ofalpha-naphthylamin in 40 parts of xylidin. Theresulting solution is suffioiently liquid so that it can be readily handled with'the ordinary oil feeders commonly employed in flotationoperations. Owing to its liquid character, and its miscibility withwater, it can be readily disseminated throughout the ore pulp, but thisdissemination can of course be promoted by agita tion.

The proportions of alpha-naphthylamin and xylidin may thus be varied tosuit the temperature of the pulp; for instance, with a pulp containingquite cold water, the dissemination of the flotation agent is promotedby relatively larger proportions of xylidin, say from 50 to 60%, withresulting advantage to the flotation operation, particularly where notvery much time is allowed to elapse between the addition of the agentand the beginning of the actual flotation, or if the pulp is notsubjectedto agitation or stirring in the meantime. On the other hand,where the water of the ore pulp is quite warm, or with suflicient timeor stirring, the amount of xylidin might be reduced to about 25 or 30%.

After the addition of the flotation agent to the ore pulp, the pulp issubjected to the flotation operation, as in an ordinary Callow cell orin apparatus where the air is incorporated in the ore pulp by mechanicalagitation. With some ore pulps it may be desirable to add either smallamounts of acids or of alkalis, depending upon the nature of subject theore pulp to agitation with a small amount of lime prior to the additionof the flotation agent thereto. This lime may serve to neutralize smallamounts of acid present, or it may act upon the slime or colloidalconstituents of the ore pulp, or it may have some other action. Whateverthe theoretical explanation of this action may be, a further markedimprovement in the flotation process, in which the flotation agentsabove referred to are employed, has been noted when lime has thus beenpreliminarily employed. The preliminary agitation with lime shouldpreferably be eifected in the ball mill or other grinding machinery inwhich the ore is pulverized with water.

The following example will further illustrate the invention, as carriedout on a copper sulfid ore (of the Utah Copper Co.).

The ore was preliminarily agitated with lime in the proportions of 4pounds of lime per ton of ore (i. e., solids in the ore pulp). It wassubjected to a flotation operation in a Callow cell with the addition ofthreefourths of a pound, per ton of ore, of the composite reagent madeup of about 60% alpha-naphthylamin and 40% of xylidin.

The original ore treated contained 0.941% of copper. The resulting tailscontained 0.145%; the' resulting concentrate 37.60%; indicating arecovery of 84.90% of the total copper.

The amount of the solution of alphanaphthylamin in xylidin .may bevaried somewhat, for example, between one half pound or less and one andone-half pounds per ton of ore, (that is calculated on the weight of theore and not of the ore pulp).

' Such amounts have been found suitable. for

:with' a silicious gangue.

example, with porphyry ores of Utah, which are mainly chalcopyrite andchalcocite ores, With such ores I have used to advantage-from 2 to 4pounds of lime per ton of ore in a treatment preliminary to the additionof the flotation agent.

.Another advantageous composition for use as a flotation agent in theprocess of the present invention is a solution of alphanaphthylamin inquinolin. Quinolin itself has advantages as a flotation agent, and, inthe composition just referred to, such advantages are retained, as wellas the other iadvantages characteristic of the composiion.

-"It is a characteristic of the process of the invention that the frothobtained is readily broken up, and that part of the flotation agent canbe recovered therefrom so that it is available for use-inthe t e ment offurther amounts of ore. That is to say, the circuit water recovered fromthe concentrate, and even that recovered from the tailings containsnotable amounts of the ingredients of the compound flotation 'agentwhich can be thus returned to the process with resulting economy in theamount required to be added for subsequent operations.

It is a further characteristic advantage of the invention, when thesolution of alphanaphthylamin in xylidin is employed, that the markedselective qualities of the alphanaphthylamin are supplemented by themarked frothing qualities of the xylidin, so that both good selectiveaction and a good frothing action is obtained. Moreover, the xylidin isitself a flotation agent so that it will supplement and replace to aconsiderable extent the action of the alpha-naphthylamin, so that lessof the alpha-naphthylamin is required, when used in solution in thexylidin, than when used alone. Accordingly, from one view point theprocess of the present invention may be considered to involve thecarrying out of the flotation operation with a compound flotation agent,comprising two or more amino compounds, having a marked selective actionand good frothing qualities.

I do not claim herein the compound flotation agents per se inasmuch asthese form the subject matter of a separate application, Serial Number265,164, filed December 3, 1918.

I claim:

1. The method of eflecting the concentration of minerals by flotation,which comprises adding to the mineral pulp a small amount of a compoundflotation agent comprising a mixture of a plurality of amino compounds,and subjecting the resulting mixture to a flotation operation,substantially as described.

2. The method of eflecting the concentration of minerals by flotation,which comprises adding to the mineral pulp a small amount of a compoundflotation agent made up of a solution of a solid amino compound in aliquid amino compound readily miscible with water, and subjecting theresulting mixture to a flotation operation, substantially as described.

3. The method of effecting the concentration of minerals by flotation,which comprises adding to the mineral pulp a small amount of a compositeflotation agent comprising a mixture of amino compounds having markedselective action and good frothing qualities, and subjecting theresulting mixture to a flotation operation, substantially as described.

4. The method of effecting the concentration of minerals by flotation,which comprises adding to the mineral pulp a solution of a solid'aomatlc ammo compound in a liquid aromatic amino compound, and subjectingthe resulting mixture to a flotation operation, substantially asdescribed.

5. The method of effecting the concentration of minerals by flotation,which comprises adding to the mineral pulp a solution ofalpha-naphthylamin in a liquid amino compound readily miscible withwater, and subjecting the resulting mixture to a flotation operation,substantially as described.

6. The method of efl'ecting the concentration of minerals by flotation,which comprises adding to the mineral pulp a solution ofalpha-naphthylamin in xylidin, and subjecting the resulting mixture to aflotation operation, substantially as described.

7. The method of eifecting the concentration of minerals 'by flotation,which comprises adding to the mineral pulp a solution of about 60 partsof alpha-naphthylamin in about 40 parts of xylidin, and subjecting theresulting mixture to a-flotation operation, substantially as described.

8. The method of incorporating with mineral pulp to be concentrated byflotation a solid amino compound which comprises dissolving such solidamino compound in a liquid amino compound readily miscible with water,and adding the resulting solution to the mineral pulp, substantially asdescribed.

9. The method of incorporating alphanaphthylamin with the mineral pulpto be concentrated by flotation which comprises dissolving thealpha-naphthylamin in a liquid amino compound readily miscible withwater, .and adding the resulting solution to the mineral pulp to beconcentrated, substantially as described.

10. The method of incorporating alphanaphthylamin with the mineral pulpto be concentrated by flotation which comprises dissolving thealpha-naphthylamin in xylidin and adding the resulting solution to themineral pulp to be concentrated, substantially as described.

In testimony whereof I aflix my si ature.

OLEMEN T LINWOOD PERl 1'

